I’m no expert, but I think the basic story is, before labor and safety laws, there was this one company that was mass producing these glow in the dark watches. One of the key ingredients that made the watches glow was radium, which is highly harmful when exposed to the human body. The people who owned the factories knew this, but to save a few bucks they didn’t implement any form of safety measures for the factory girls who were hand painting the watches. In fact, they encouraged the girls to keep the tips of their paint brushes sharp by sucking on them with their mouths, causing them to ingest traces of the radium paint frequently. It was the cheapest and most efficient method. They lied and told the girls that eating a little radium was good for their health. A lot of the girls got very, horrifically sick. Like, crazy wasting away and body pieces falling off if them while still alive kind of sick. When the story got out, there was an uproar, and there were laws implemented, but I think I heard the company got off relatively easy in the end.